1. Field of the Invention
This invention relates to selected derivatives of 2-selenopyridine-N-oxide and their use as fungicides and bactericides.
2. Description of the Prior Art
Various selenium compounds have been known to possess different types of pesticidal activity such as fungicidal, bactericidal, and the like. In particular, selenium disulfide is a known antidandruff agent. See U.S. Pat. No. 2,644,669, which issued to Baldwin et al. on Nov. 16, 1954.
H. Mautner, S. Chu and C. Lee, in J. Org. Chem., 27, pages 3671-3673 (1962), disclose the synthesis of 2-selenopyridine-N-oxide from 2-bromopyridine-N-oxide and hydrogen selenide. However, the authors do not mention that this compound has any fungicidal or bactericidal activity, nor do they state that this compound may be converted into salts, chelates, or other derivatives.
Separately, the sodium salt and the zinc chelate of 2-mercaptopyridine-N-oxide, along with the di(sulfide) derivative in which two pyridine-N-oxide nuclei are connected by two sulfur atoms, have all been shown to be broad spectrum antimicrobial agents. These 2-mercaptopyridine-N-oxide compounds are especially effective against a wide variety of fungi as well as bacteria. They have found commercial use as industrial biocides in both metalworking fluids and cosmetics. However, they have not been employed commercially as agricultural pesticides because they degrade in the presence of light.